Relay



p 9 V F. B. YHITCHCOCK 2,056,147

RELAY Filed Aug. 11, 1934 FIG.1.

FIG. 3. FIG .4.

BY MMM 4i ATTORNE-Y Patented Sept. 29, 1936 PATENT OFFICE RELAY ForestB. Hitchcock, Greece, N. Y., assignor to General Railway Signal Company,Rochester,

Application August 11, 1934, Serial No. 739,468

11 Claims.

This invention'relates in general to relays, and has more particularreference to a relay of the retained neutral tractive type with orwithout a polar armature.

It is often desirable to have a relay slow to release relative to itspick up time; slow to pick up relative to its release time; both slow topick up and slow to release; and also to have a neutral armature whichwill remain picked up upon a quick reversal of current in its operatingwindings.

The present invention proposes to provide the above mentionedcharacteristics, in an improved manner, by the provision of an auxiliaryholding magnet for the neutral armature of a tractive type relay, whichholding magnet is inductively coupled with the operating winding in sucha manner as to be uniformly eliective to accomplish its retaining andretarding functions.

The present invention is to be considered as an improvement over therelays disclosed in the prior patent, Patent No. 1,852,210, dated April5, 1932, to F. C. Larson.

Other objects, purposes and characteristic features of the presentinvention will be in part obvious from the accompanying drawing, and inpart pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to theaccompanying drawing, in which like reference characters provided withdistinctive exponents designate corresponding parts throughout theseveral views, and in which:

Fig. 1 is a diagrammatic illustration of a retained neutral polar relayconstructed in accordance with the present invention.

Fig. 2 illustrates in a diagrammatic and conventional manner a secondform which the present invention may assume; and

Figs. 3 and 4 are fragmentary sectional views of Fig. 1 taken on lines33 and 44 respectively and looking in the direction of the arrows tomore clearly bring out the diagrammatic construction illustrated.

Referring to Fig. l of the accompanying drawing, a relay is shown ascomprising an operating magnet OM, a holding magnet HM, a neutralarmature NA, a polar armature PA and a bridge rectifier R. The relay iscontrolled by a lever L which suitably supplies energy from a battery B.This type of control is shown merely to illustrate the operation.

The operating magnet OM of the relay comprises two core members 4 and 5having pole pieces 6 and 1 respectively, which core members areconnected by a back strap 8. Operating windings 9 and Ill are located onthe core members 4 and 5 respectively. Auxiliary windings H and I2 arealso located on the core members 5 4 and 5 respectively.

As here shown, the windings 9 and ID are spaced apart from the windingsH and [2 on their respective core members, but this arrangement is shownonly for. the purpose of making 10 the disclosure clear, it beingunderstood that in actual practice the windings 9-H and windings Iii-l2will usually be wound in the same coils, or otherwise closelyinductively associated.

The operating windings 9 and ID are supplied with operating current fromthe battery B through pole changing contacts I3 and M of the lever L toreverse the polarity on the operating windings or to open the circuit,depending upon Whether the lever L is operated to extreme positions orto an intermediate position.

The holding magnet comprises core members l5 and it connected at the topby back strap l1. Holding coils l8 and I9 are respectively located onthe core members l5 and I6 and conductively connected to the auxiliarywindings H and 12 through a bridge rectifier R comprising asymmetricunits 20, 2|, 22 and 23. The direction of relatively low conductivitythrough these asymmetric units or rectifiers is indicated by the arrows.These asymmetric units 20, 2|, 22 and 23 may be of any suitable type,such as the copper-oxide dry plate rectifier or the electrolytic typerectifier.

The core members I 5 and I6 of the holding magnet HM are provided withupper pole pieces 24 and 25 respectively, and also With lower polepieces 26 and 2! respectively. The pole pieces 24 and 26 are connectedby a U shaped portion 28; and similarly, the pole pieces 25 and 21 areconnected by a U shaped portion 29. This will be best understood bynoting Fig. 4.

The neutral armature NA is pivoted at the point 36 and has a portion 3|associated with the pole pieces 6 and 1 of the operating magnet OM and aportion 32 associated with the pole pieces 24, 25, 26 and 2'! of theholding magnet HM. The portions 3| and 32 of the neutral armature NA areboth magnetically and electrically insulated from each other by aportion 33. This neutral armature NA is adapted to be attracted to apicked up position, as illustrated in the drawing, or to assume adropped away released position when the operating magnet OM isdeenergized and the holding magnet has ceased to have a holding effecton the armature, as hereinafter described. As shown, the releasingtendency or bias of the neutral armature is provided by gravity.

The armature portion 3I is prevented from residual pins 36 and 31, andis also prevented from coming into contact with pole pieces 26 and 27 bynon-magnetic residual pins 38 and 39.

Mounted upon the neutral armature NA on the insulating portion 33 is acontact member 49 which cooperates with front contact M and back contact42. The contacts 40, 4| and 42 are conductively connected to bindingposts 43, 44 and 45 respectively.

Also, associated with the pole pieces 6 and I is a polar armature PAwhich is formed of a permanent magnet having pole faces N and S whichare adapted to be attracted and repelled in accordance with the polarityof the pole pieces 6 and I. Ihis polar armature PA is pivoted at point46 and extends in sort of a U shaped fashion about the neutral armatureNA as illustrated in Fig. 3.

Mounted on the polar armature PA and electrically insulated therefrom isa movable contact 41 which is electrically connected with binding post48 and cooperates with front contact 49 and back contact 59 which arerespectively connected to binding posts SI and 52.

It is to be understood that the polar armature PA may be of any suitabletype so far as the present invention is concerned, it being sufficientfor an understanding of the present invention to know that a polararmature may be associated with the operating magnet OM in any suitableway shown in the prior art such as for example in the Patent No.1,852,210, to F. C. Larson.

With reference to Fig. 2 of the accompanying drawing, a relay isillustrated which is arranged and controlled in a similar manner asdescribed for Fig. l. 'The corresponding parts of Fig. 2 are designatedby corresponding reference characters with the'distinctive exponent 2.The difference in structure of Fig. 2 over Fig. 1 is that the rectifierR is not of the bridge type but comprises only asymmetric units 53 and54. These units have the same characters as mentioned for the units ofthe rectifier R in connection with Fig. 1 but are associated with theauxiliary windings and holding windings in somewhat different manner, aswill be described hereinafter.

It is believed that the nature'of the invention, its advantages, andcharacteristic features can be best understood with further descriptionbeing set forth from the standpoint of operation.

Operation As illustrated, the relays of Figs. 1 and 2 are shown as beingenergized. The neutral armatures NA and NA are therefore in picked uppositions. The actuation of the levers L and L to mid-positions opensthe energizing circuit for the operating coils of the operating magnetsand thereby allows the neutral armatures to drop away'subject to theeffect of the holding magnets'HM, as hereinafter pointed out.

With the operating magnets energized, as 11'? lustrated, the polararmatures PA and PA are operated to positions as illustrated, but uponthe operation of the levers L and L to opposite extreme positions, thepolar armatures PA and PA are respectively operated to oppositepositions in accordance with the well known laws of magnetism by reasonof the reversal of the polarently to be set forth.

It is to be understood that the levers L and L may be operated tomid-positions or to opposite,

positions in any sequence whatsoever, and such control is not limitedto'a manual operation but may be automatic control of any typewhatsoever.

With more specific reference to Fig. 1 of the accompanying drawing,consideration will now 'be given to the effect that the holding magnetHM has upon the neutral armature NA under various conditions of removalof energy and the application of energy of opposite polarities invarious sequences.

The operation of the contacts I3 and I4 to midpositions deener-gizingthe operating coils 9 and' I9, causes the dying out of the flux in theoperating magnet OM. Such collapse of the flux in the operating magnetinduces a potential in the coils II and I2 which causes a current toflow from the. upper terminal of coil I2 through wire 55, rectifier unit2|, coil I9, coil I8, rectifier unit 23, wire 56, coil II, to the lowerterminal of the coil I2. This flow of current in the windings I8 and I9produces a magnet flux in the holding magnet HM which attracts thearmature portion 32 toward the pole pieces 24 and 25. This attractionoccurs subsequent to the opening of the circuit by contacts I3 and I4and tends to hold the neutral armature NA picked up until the inducedcurrent in the coils II and I2 dies to a predetermined low value.Therefore, the drop away of the neutral armature NA is thereby delayed.

After the neutral armature NA is droppedaway and the armature portion 32is in contact with the residual pins 38 and 39, let us assume that thelever L is actuated so as to return contacts I3 and It to the positionillustrated. This energizes the coils 9 and I9 with current, whichcauses the building up of the magnetic flux in the operating magnet OM,which in turn induces current in the coils II and I2 which flows fromthe upper terminal of coil II to wire 56, rectifier unit 20, winding I9,winding I8, rectifier unit 22, wire 55, coil I2, to the lower terminalof the coil II. The current thus induced in the windings II and I2energizes the coils I8 and I9 of the holding magoperating magnet flowsin an opposite direction in the coils I I and I2 from that direction inwhich the induced current flows upon the breaking of the controllingcircuit. If it were not for the rectifier unit R (and coils I8 and I9were connected in series with coils II and I2), this reversal of ourrentwould be effective to energize the coils l8 and Not the holding magnetHM in opposite directions. Thus, the magnetic flux produced by theinduced current for each successive operation must counter-act theresidual magnetism remaining from the preceding operation which wouldthereby reduce the total holding or retaining effectiveness of theinduced current. However,

with the rectifying unit R provided in accordance with the presentinvention, the coils l8 and I9 are always energized in the samedirection by the induced currents so that the magnetic flux always flowsin the holding magnet HM in the same direction and does not have to passthrough zero. This provides for additional efficiency in the retainingeffect of the holding magnet HM.

If the operating coils 9 and ID of the operating magnet OM were alwayssuccessively deenergized and energized with the same polarity, and therectifier R was omitted, then the resulting holding effect, even thoughreduced by reason of the residual which must be bucked down each time,would always be uniform. But, it might happen that the operating coils 9and IU of the operating magnet OM would be energized with successivelyopposite polarities, and in such cases the retaining effect of theholding magnet HM would not be uniform. As provided in accordance withthe present invention, the rectifying unit R causes a uniform holdingeffect even under such circumstances. This is because the currentinduced in the coils I I and I2 upon the breaking of the operatingcurrent is in a direction which corresponds to the direction of thecurrent induced when the operating coils are energized with the oppositepolarity. Thus, it will be evident that if the rectifying unit H. werenot provided, the coils l8 and [9 of the holding magnet HM would berequired to buck the residual when the operating magnet is reenergizedwith the same polarity, but would not be required to buck the residualwhen the operating magnet is reenergized with the opposite polarity,thereby making the retaining effect vary in accordance with theparticular sequence of polarity applied to the operating magnet OM.However, the arrangement provided in accordance with the presentinvention causes the holding magnet HM to operate uniformly andefficientiy under all circumstances of opening and closing of theoperating circuit as well as when the direction of current flow isreversed.

It is apparent that the polar armature PA responds to the reversal of.the direction of current flow in the operating coils 9 and I!) of theoperating magnet, and it may be desirable under certain circumstances toreverse the polarity of current on the operating coils to cause theoperation of the polar armature PA without the dropping away of theneutral armature NA. In an ordinary polar neutral relay, such reversalof energy on the operating coils causes the magnetic fiux in theoperating magnet to pass through zero and the neutral armature alwaysassumes a dropped away position, at least momentarily, irrespective ofhow quickly the polarity may be reversed.

In accordance with the present invention, the holding effect of theholding -magnet HM acting upon the portion 32 of the neutral armature,which portion 32 is magnetically insulated from the portion 3!, is ofsufficient duration upon the reversal of current in the operating magnetOM to cause the neutral armature NA to be maintained picked up and allowthe polar armature to operate in response to the reversal of polarity.

This of course requires that the reversal of polarity be accomplishedwithin a predetermined time dependent upon the total time during whichthe holding magnet HM will maintain the neutral armature NA picked up.This holding effect or retaining effect may be expressed in other termsby stating that the magnet fluxes in the portions 3| and 32 of theneutral armature NA do not pass through zero at the same time. In fact,the magnetic flux in the portion 3! of the neutral armature is the onlyflux which passes through zero upon the reversal of polarity, whereasthe flux in the portion 32 of the neutral armature only approaches zero.This is due to the rectifying unit R provided in accordance with thepresent invention.

With reference to Fig. 2 of the accompanying drawing, the resultingeffect upon the neutral armature NA is exactly the same as thatdescribed for the neutral armature NA of Fig. 1, but the rectifyingunits 53 and 54 replace the units 20, 2|, 22 and 23 of the rectifyingunit R. In other words, the coils H and I2 together with the rectifyingunits 53 and 54 take the place of the bridge rectifier R.

In this Fig. 2, considering the opening and closing of the operatingcircuit, as occurring successively, the coils H and I2 are effectiverespectively on such successive operations to provide the inductivecurrent for the coils l8 and I9 It is believed that this result will bereadily apparent to those skilled in the art. The main advantage of thearrangement shown in Fig. 2 is that of the simplification of theapparatus employed.

Although the holding magnets HM and HM are illustrated as having bothfront and back pole pieces, it is to be understood that the arrangementmay be supplied in accordance with the present invention in anycombination, that is, without either front or back pole pieces.

For example, the pole pieces 24 and 25 may be so arranged as to noteffect the portion 32 of the armature NA to thereby cause the holdingmagnet to be effective through the pole pieces 26 and 2'! to cause aretained or detained pick up of the neutral armature but not effect therelease of such armature. It is of course readily apparent that theopposite condition might be set up by the removal of the pole pieces 25and 2'! so as to provide a slow releasing or retained neutral relay withregard to the drop away, but not effect the pick up characteristics.

Thus, the present invention provides a holding magnet in connection witha neutral armature of a relay, so associated inductively with theoperating magnet of the relay that it is always effective to the sameextent irrespective of whether the same or opposite polarities areapplied successively through the operating winding, and also to providethe greatest efiiciency in the case of the opening and closing of theoperating circuits successively without a reversal of polarity.

Having thus described a relay structure and control therefor as onespecific embodiment of the present invention, it is desired to beunderstood that these forms are selected to facilitate in the disclosureof the invention rather than to limit the number of forms which it mayassume; and it is to be further understood that the various adaptations,modifications, and alterations may be applied to the specific form shownto meet with the requirements of practice, without in any mannerdeparting from the spirit or scope of the invention except as limited bythe appended claims.

What I claim is:

1. In a relay structure, a main armature, a retaining armature, means ofnon-magnetic material for rigidly connecting said armatures, anoperating winding for the main armature, a retaining winding for theretaining armature, and means for furnishing unidirectional current tosaid retaining winding which current is inductively generated by achange in current in said operating winding. 7

2. In a relay structure, a main armature, a retaining armature, means ofnon-magnetic material for rigidly connecting said annatures, anoperating winding for the main armature, a retaining winding for theretaining armature, an auxiliary winding inductively coupled to saidoperating winding, means connecting said auxiliary and said retainingwindings in series, and means allowing only unidirectional current toflow in said retaining winding.

3. In a relay structure, a main armature, a retaining armature, means ofnon-magnetic material for rigidly connecting said armatures, anoperating winding for the main armature, a retaining winding for theretaining armature, an auxiliary winding inductively associated withsaid operating winding, a bridge connected asymmetric unit, and circuitmeans connecting said retaining and auxiliary windings in series throughsaid asymmetric unit.

4;. In a relay structure, a main armature for operating contacts, anoperating winding for actuating said main armature, a retaining armaturedirectly and rigidly connected to said main armature but magneticallyinsulated therefrom, a retaining winding for acting upon said retainingarmature, an auxiliary winding inductively associated with saidoperating winding whereby any change in current value in said operatingwinding induces a current in said auxiliary winding, circuit meansconnecting said retaining winding in series with said auxiliary winding,and rectifier means for causing all induced currents in said auxiliarywindings to flow in the same direction in said retaining winding.

5. In a relay structure, a main armature for operating contacts, anoperating winding for acting upon said main armature, a retainingarmature directly and rigidly connected to said main armature butmagnetically insulated therefrom, a retaining winding for acting uponsaid retaining armature in a direction corresponding to the directionthat said operating winding acts on said main armature, an auxiliarywinding inductively associated with said operating winding whereby anychange in current value in said operating winding induces a current insaid auxiliary winding, circuit means connecting said retaining windingin series with said auxiliary winding, and rectifier means for causingall induced currents in said auxiliary winding to flow in the samedirection in said retaining winding.

6. In a relay structure, a main armature for operating contacts, anoperating winding for' acting upon said main armature, a retainingarmature directly and rigidly connected 'to said main armature butmagnetically insulated therefrom, a retaining winding for acting uponsaid retaining armature in a direction opposite to the direction thatsaid operating winding acts on .said main armature, an auxiliary windinginductively associated with said operating winding whereby any change incurrent value in said operating winding induces a current in saidauxiliary winding, circuit means'connecting said retaining winding inseries with said auxiliary winding, and rectifier means for causing allinduced currents in said auxiliary winding to flow in the same directionin said retaining winding.

7. In a relay structure, a main armature for operating contacts, anoperating winding for acting upon said main armature to pick it up or.drop itaway, a retaining armature directly and rigidly connected to saidmain armature but magnetically insulated therefrom, a retaining windingfor acting upon said retaining armature in one direction or the otherdepending upon whether said main armature is picked up or dropped away,an auxiliary winding inductively associated with said operating windingwhereby any change, in current, value in said operating winding inducesa current in said auxiliary winding, circuit means connecting saidretaining winding in series with said auxiliary winding, and rectifiermeans for causing all induced currents in said auxiliary winding to flowin the same direction in said retaining winding. 7

8. In a relay structure, a main armature for operating contacts, anoperating winding for actuating said main armature, a retaining armaturedirectly and rigidly connected to said main armature but magneticallyinsulated therefrom, a retaining winding comprising two coils for actingupon said retaining armature, an auxiliary winding inductivelyassociated with said operating winding whereby any change in currentvalue in said operating winding induces a current in said auxiliarywinding, circuit means for connecting said two coils in multiple witheach other and in series with said auxiliary winding, and rectifiermeans in series with each of said coils so as to allow current to fiowin one direction in one of said coils and in the opposite direction inthe J other of said coils.

9. In combination, a source of direct current, an inductorhaving twowindings, means for connecting one of said windings with anddisconnecting it from said source, an electro-responsive device, arectifier, and circuit means connecting said electro-responsive devicewith the other of said windings of said inductor through said rectifier.V

10. In combination, a source of direct current, an inductor having twowindings, means for at times connecting one of said windings with anddisconnecting it from said source with one p-olarity and for at timesconnecting said one of said windings with and disconnecting it from saidsource with the opposite polarity, an electro-responsive device, a fullwave rectifier, and circuit means connecting said electro-responsivedevice with the other of said windings of said inductor through saidfull wave rectifier. V

11. In combination, a source of direct current, 'a relay having anarmature and two windings, means for connecting one of said windingswith and disconnecting it from said source, an electro- -magnet at timesexerting a force on said armature, a rectifier, and circuit meansconnecting said electro-magnet with the other of said windings of saidrelay through said rectifier.

FOREST B. HITCHCOCK.

